By Jenna Portnoy and Jarrett Renshaw/Statehouse Bureau Staff
TRENTON — Before Chris Christie could make his case for the support of the building trades union in 2009, powerful labor leader Ray Pocino had already made up his mind.

Gov. Jon Corzine, the Democrat, was his man.

But today Christie — the Republican who upended Corzine to become the governor — will reap the rewards of a three-year courtship of private sector unions when he accepts Pocino’s endorsement for a second term, according to three Democrats briefed on the plan.

Pocino is vice president of the Laborers’ International Union of North America, which represents 20,000 construction workers in New Jersey, and he is expected to appear with Christie at noon today at the Laborers Local 472 training center in Aberdeen. It will be Christie’s first public campaign event.

"This is indicative of the governor’s strength and increased strength from 2009," a Republican with knowledge of the endorsement said. "This is a takeaway from whoever the eventual Democratic candidate is and demonstrates just how strong the governor is going into an election year."

Democrats like Senate President Steve Sweeney — a top official of the state ironworkers union — are biding their time, waiting to see if Newark Mayor Cory Booker enters the governor’s race. One exception is state Sen. Barbara Buono (D-Middlesex), who announced her candidacy last week.

The endorsement turns the political landscape on its head in a state where registered Democrats, who outnumber Republicans by some 700,000 voters, have long counted on union support — though Pocino has crossed over in the past.

He was among the first in a wave of labor leaders to endorse Gov. Christie Whitman over her Democratic challenger, Mayor Jim McGreevey of Woodbridge, in 1997. When McGreevey was elected four years later, he appointed Pocino to the board of the Port Authority of New York and New Jersey, and Christie has kept him on. Pocino is also in his fifth term as a member of the Turnpike Authority.

"The governor has worked hard at that relationship, appointing him to the Port and Turnpike authorities," Assemblyman Thomas Giblin (D-Essex), a former state Democratic chairman and business manager of the International Union of Operating Engineers, based in West Caldwell, said.

Christie often draws a line between public sector unions, who rely on taxpayer support and with whom he fought bitterly, and members of private unions.

"I am against anybody in this state having to carry other people’s benefits unfairly on their own backs," he has said.

Pocino was a co-chairman of Building our Future, a bipartisan committee that encouraged voters last month to let the state borrow $750 million to finance such higher education projects as new laboratories and classrooms.

Christie pushed for the spending on that initiative as well as on the School Development Authority’s plan to build and renovate dozens of public schools.

The union leader’s endorsement also shows the building trades haven’t held a grudge over Christie’s decision two years ago to halt construction of a multibillion-dollar Hudson River commuter train tunnel linking New Jersey and midtown Manhattan.

"We’re taxpayers, too," Assemblyman John Amodeo (R-Atlantic), a longtime member of the operating engineers union, said. "We have a proven supporter with Governor Christie. He gets us."

The mutual admiration was on display in May when Christie spoke at the union’s eastern regional conference at Harrah’s Resort in Atlantic City. Pocino introduced him as "New Jersey’s own wrecking ball governor" and played a video showing him shoveling dirt and shaking hands with construction workers in hard hats.

Christie pushed for completion of the $2.4 billion Revel casino, where the ownership had changed hands and work had stalled, and American Dream, the troubled $3.7 billion entertainment complex at the Meadowlands that had been known as Xanadu.

And he has said he expects the $1 billion raising of the Bayonne Bridge to be "one of the proudest moments I’ll ever have as governor."

In October, Christie devoted one of his signature town hall meetings to tradesman. Hundreds of laborers packed the wood-paneled hall of Ironworkers Local Union 73 in Perth Amboy, many snacking on hot dogs fresh off the grill.